NE587 Datasheet, PDF (6/9 Pages) NXP Semiconductors – LED decoder/driver

Philips Semiconductors Linear Products
LED decoder/driver
Product specification
NE587
TYPICAL PERFORMANCE CURVES
Supply Current vs Supply Voltage
40.0
35.0
I_{CC 30.0}
(mA)
R_P = 1kΩ
V_OUT = 2V
ALL OUTPUTS “ON”
(0°C)
(25°C)
(70°C)
25.0
Output Current vs Output Voltage
R_P = 1kΩ
40.0
(0°C)
(25°C)
30.0
20.0
I_OUT
(mA)
10.0
(70°C)
Normalized Output Current vs
Temperature V_CC = 5.0V
110.0
105.0
I_OUT
(%)
100.0
NE587
R_P = 1kΩ
95.0
20.0
4.0 4.4 4.8 5.2 5.6 6.0 6.4
V_CC (VOLTS)
Normalized Output Current vs Supply
Voltage V_O = 2V, T_A = 25°C
105
102
I_OUT
(%) ₁₀₀
98
NE587
R_P = 1kΩ
0 1.0 2.0 3.0 4.0 5.0
V_OUT (VOLTS)
Maximum Power Dissipation vs
Temperature
1000
800
P_D
(mW) ⁶⁰⁰
400
200
90.0
10 20 30 40 50 60 70 80
TEMP (°C)
Output Current vs Program Resistor
50.0
V_CC = 5.0V
V_OUT = 2V
40.0
T_A = (25°C)
30.0
I_OUT
(mA)
20.0
10.0
95
4.0 4.5
5.0 5.5 6.0
V_CC (VOLTS)
0
0
25
50
T_A (°C)
These voltages are all for single-diode displays. Some early red
displays had 2 series LEDs per segment; hence the forward voltage
drop was around 3.5V.
Thus, a maximum power dissipation calculation when all segments
are on, is:
P_D + V_CC x I_CC ) (V_S * V_F) x 7 x I_SEG
D₃
D₂
x K_DCmW
D₁
D₀
Assuming V_S = V_CC = 5.25V
V_F = 2.0V
K_DC = 100%
LE
P_{D MAX} = 5.25 × 50 + 3.25 × 7 × 30mW = 945mW
I_P
However, the average power dissipation will be considerably less
than this. Assuming 5 segments are on (the average for all output
RBI
code combinations), then
75
0.0
0
2.0
4.0
6.0
R_P (kΩ)
V_CC
0.01µF
a
b
c
NE587 _d
e
f
g
RBO
P_{D MAX} = 5.0 × 30 + 3.00 × 5 × 25mW = 525mW
Operating temperature range limitations can be deduced from the
power dissipation graph. (See Typical Performance Characteristics.)
NOTE:
Decoupling capacitor on V_CC should be 0.01µF ceramic.
Figure 5. Driving a Single Digit
8.0 10.0
V_S
August 31, 1994
535